gitlab-org--gitlab-foss/app/graphql/queries/epic/epic_details.query.graphql

query epicDetails($fullPath: ID!, $iid: ID!) {
  group(fullPath: $fullPath) {
    __typename
    id
    epic(iid: $iid) {
      __typename
      id
      participants {
        __typename
        edges {
          __typename
          node {
            __typename
            id
            name
            avatarUrl
            webUrl
          }
        }
      }
    }
  }
}